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The synchronously periodic re-melting of molten pool was firstly introduced in additive manufactur-ing to promote the epitaxial growth of columnar structure using a novel quasi-continuous-wave (QCW) laser. The epitaxial growth of columnar structure was intensified and the single-crystal-like sample with highly oriented“zigzag”columnar grains was produced. The modified molten-pool geometry and the synchronously high-frequency re-melting of the molten pool contribute to the formation of single-crystal-like structure. This work reports a new route to promote the continuously epitaxial growth of dendrites for fabrication of single-crystal-like sample.